Control device for machines



Oct. 1, 1935. A. K. MARSH CGNTROL DEVICE FORl MACHINES 2 Sheets-Sheet l Filed April 4, 1935 www LEES:

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-7 M y v f TTORNEY L 1935. A, K MARSH CONTROL DEVICE FOR MACHINES Filed April 4, 1955 2 Sheets-Sheet 2 Patented Oct. 1, 1935 TES PATENT GPH@ CONTROL DEVCE FOR, MACHINES Alonzo` K. Marsh, Summit, N. J., assignor to A. Kimball Company, New York, N. Y.,

poration of New York Application April 4, 1935, Serial No. 14,574

6 Claims.

This invention relates to control devices for machines and particularly to safety devices adapted to protectY the machine operator from injury.

In recent years there has been an increasing demand for safety devises in connection with machines such as cutting machines, punch presses and the like, and in some states laws havey been enacted requiring that certain safeguards be provided. For example, it is sometimes required thatr the operating controls of the machine be such that the operator is required to use both hands to start the machine, the theory being that if both hands are so employed, it is unlikely that either hand will be in a dangerous position. Also it is sometimes required that the controls be such that the machine will be none repeating, that is, it will of necessity be stopped at the end of' each operating cycle and must be started again by the operator.

It is an object of the present invention to pro-4 vide a safety control device of very simple, inexpensive construction which will meet these and other requirements.

Other objects and advantages of the invention will appear hereinafter.

A preferred embodiment of the invention selected for purposes of illustration is shown in the accompanying drawings, in which,

Figure l is a top plan view.

Figure 2 is a front elevation.

Figure 3 is a composite end elevation and sectional view of the left side of the machine.

Figure 4 is a fragmentary end elevation of the right side of the machine, and l Figure 5 is a sectional view of the locking pin.

Referring to the drawings, the control device has been illustrated as applied to a cutting machine, but inasmuch as the operation of the cutting knife forms no part of the present invention, the operating mechanism is not illustrated, although the cutting knife I is indicated semidiagrammatically in Figures 1, 2 and 3 in order to indicate its position relative to the control devices. It will be understood that the said operating mechanism includes a conventional clutch.

lever, the said clutch lever 2 being connected to the usual clutch (not shown) through any suitable connections (not shown) Means are provided for'lockingthe parts 2 and 3 together in order that they mayoperate asa 5 unit to control the clutch, and the said means may comprise a pin 5 mounted in an aperature 6 in the clutch handle, and which may be depressed to cause the end of the pin 5 to enter the aperture l' in the lever 2. The pin is norl0 mally held out of the aperture 'l by the coil spring 8 which is interposed between the clutch handle 3 and the head 9 of the pin.

Means are provided for operating the pin 5 comp-rising a lever Il mounted on a shaft I2 l5 carrying a cam plate i3 located above the pin 5 and normally in engagement with the head t of the pin. As will be observed, the clutch handle 3 and the lever I I are located at opposite ends of the worketable lf3 at positions separated far enough so that it is impossible for the operator to operate both levers with one hand.

It will also be observed that itis necessary for the operator to move both levers in order to move the clutch lever 2 to start the machine. Thus, since the pin 5 is normally out of engagement with the lever 2, movement of the clutch handle 3 will have no effect, since the handle 3 will merely swing about its pivot 4. In order to operate the machine, therefore, the operator must 30 rst move the handle 3 to bring the apertures t and 1 into register, and then move the lever ll to cause the cam plate I3 to depress the pin 5. When the pin 5 has entered the aperture, the clutch lever 2 may be moved to the operating 35 position by moving the clutch handle 3. If either the clutch handle 3 or the lever Il is released by the operator at any time, the machine will be stopped immediately, for if the handle 3 is released, the lever 2 is restored to normal non 40 operating position by the spring l5 which connects the lever 2 to a fixed part of the machine such as the leg I 6, thus disengaging the clutch and stopping the machine. If the clutch of the machine is supplied with a spring tending to dis- 45 engage the same, the spring I5 may be dispensed with, or if desired, the spring I5 may be used to supplement the usual clutch spring. On the other hand, if the lever II is released while the machine is in operation, the spring 3 lifts the pin 5 out of aperture 1, thus disengaging the handle 3 from the lever 2 and permitting the lever 2 to return to normal position under the iniiuence of the spring l5 or the clutch spring, thus stopping the machine. It will be observed 55 pin out of that the cam plate I3 is of sufficient area to engage the pin 5 vduring the entire movement of the lever 2 and handle 3 from their normal nonoperating positions as illustrated in Figures l and 2 to their operating or clutch engaging positions somewhat to the left.

Means may also be provided for automatically causing a disengagement of the clutch at the end of each operating cycle of the machine. Such means may comprise a bell crank I6 pivotally mounted on the support l1 and having an arm I8 which engages a trip cam I9 mounted on the operating shaft 2o of the machine. The other arm 2l is arranged to engage the under side of the lever 22 on the shaft l2, the arrangement being such that at the end of each operating cycle the trip cam IQ will operate the bell crank to cause the shaft l2 to be moved to lift the cam plate I3 thus permitting the pin v5 to move out of the aperture l, thus causing the machine to stop.

lt will loe-understood that the invention may be variously modied and embodied Within the scope of the subjoined claims.

I claim as my invention:

l. A safety control device comprising an operating lever comprising two pivotally connected parts, one of said parts being adapted for operative connection to a clutch of the machine to be controlled, resilient means tending to hold said part normally in non-operating position, a

pin mounted on one of said parts, said other part being provided with an aperture adapted to receive said pin so as to lock the parts together, resilient means normally tending to hold said said aperture, a second operating lever, a cam operated by said second lever tor operating said pin to push the same into said aperture and holding the same therein while said rst operating lever ismoved to operating posi-A tion.

2. A safety control device comprising an operating lever comprising two connected relatively movable parts, a second operating lever, means including a pin mounted on one of said parts and a cam operated by said second operating lever for operating said pin to prevent movement between said relatively movable parts while permitting them to move together to control the operation of a machine.

3. A safety control device comprising an operating lever comprising two connected relativelyY movable parts, while permitting them to move together to control the operation of a m'achine.

Y 5. A safety control device comprising an operating lever comprising two connected relatively movable parts, a second operating lever, means operated by said second operating lever for preventing movement between said relatively movable parts, while permitting them to move together to control the operation of a machine; and Y means operated by the machine for operating said second operating lever to release said relatively movable parts upon completion of one operating cycle of the machine.

6, A safety control device comprising an operating lever comprising two connected relatively movable parte, a second operating lever, means including a pin mounted on one of said parts and a cam operated by said second operating lever for operating said pin to prevent movement between said relatively movable parts while permitting them to move together to control the operation of a machine, and means operated by the machine for releasing said pin upon completion of one operating cycle of the machine.

ALONZO K. MARSH. 

